The present invention relates to a single reagent system and method designed to detect and measure oxidizing adulterants in urine, sweat, saliva, blood or other bodily fluids being screened for drugs of abuse. Specifically, the present invention is directed to detect and measure sodium hypochlorite (bleach), chlorine, hydrogen peroxide, sodium bromide, sodium iodide, sodium nitrite and pyridinium chlorochromate adulterants in urine during screening for drugs of abuse.
As the use of illicit drugs in public, workplace, sports and the like has grown, public concern for the health and safety of individuals and the negative impact of such drugs use on productivity of industry has grown as well. Such concern obligated the use of analysis of urine, sweat, saliva, blood, or other bodily fluids, as a way to detect and defer drug use. Such testing for drugs of abuse in industry for prospective and current employees, particularly government employees, military personnel, professional and amateur athletes, truck drivers, pilots, as well as people under supervision of the criminal justice system, has become a routine practice.
Because of the significance of a positive result in such testing commonly performed by examining an urine, sweat, saliva, blood or other bodily fluids sample, the testing procedure must withstand vigorous scrutiny. A positive test result of screening for drugs of abuse can have serious impact on the life of a person being tested. The incentive for a user to alter the test specimen is high. The users of drugs of abuse have developed ways to adulterate the collected specimen in an attempt to produce a false negative result in the drug screening test being conducted.
A drug user may affect the test results by dilution reduce the drug concentration in the urine sample; substitution with liquids such as clean (drug-free) urine, apple juice, tea, soda for the drug containing specimen; or adulteration- addition to the urine specimen of foreign substances in an attempt to invalidate the test.
Such adulteration of urine sample can be achieved by the addition of several readily available agents, including household products; i.e. bleach (sodium hypochlorite), chlorine, sodium bromide, sodium iodide, hydrogen peroxide, pyridinium chlorochromate finger nail polish remover, Visine, soap, together with commercial available adulteration products, such as xe2x80x9cURINE-AID(copyright)xe2x80x9d (gluteraldehyde), and xe2x80x9cKLEA(copyright)xe2x80x9d (sodium nitrite).
Additionally, drug users may eliminate some drugs rapidly from their bodies by altering their urinary pH. This includes using NU4Cl to hasten the elimination of phencyclidine or amphetamines from the bodies.
While the use of some in vitro adulterants can be eliminated by the direct observation of the test subject during the collection process, such direct observation is often deemed unacceptable.
Such adulteration can affect the four commonly used methods for drugs of abuse, namely: enzyme immunoassay (EIA or EMIT), lateral flow immunoassey (LFIA), radioimmunoassay (RIA) and florescent polarization Immunoassay (FPIA). Thus, clinical chemistry literature recommends that adulterants be tested prior to testing of drugs of abuse in urine samples.
Accordingly, a need exists for providing an easy and convenient manner by which to make a determination of the presence of oxidizing adulterants in urine samples prior to the testing for drugs of abuse. Particularly, the need exists to provide an easy and convenient manner to detect bleach, chlorine, sodium bromide, sodium iodide, hydrogen peroxide, sodium nitrite, and pyridinium chlorochromate in urine samples prior to the testing for drugs of abuse.
The patent to Ehrenkranz (U.S. Pat. No. 4,769,215) discloses a urine sample collection apparatus having ability for detecting the presence of adulterants, such as bleach, intentionally added into the urine sample to tamper or mask urine test results. The apparatus is provided with an enzyme/bleach poison detector or strip having an indicator formed from glucose oxidase, peroxidase and potassium iodide.
The patent to Smith (U.S. Pat. No. 5,464,775) discloses a method of detecting adulterants, such as bleach and gluteraldehyde, in urine samples through the use of an indicator containing essentially phenylhydrazine.
The patents to Ramana et al.(U.S. Pat. No. 5,491,404); Serrat (U.S. Pat. No. 5,783,149); and Wu (U.S. Pat. No. 5,888,758) all disclose the specific use of tetramethylbenzidine as an indicatoron a test strip (or in a kit) for detecting the presence of chlorine in water samples.
The patents to Gretton et al. (U.S. Pat. No. 3,290,228); Magers et al. (U.S. Pat. No. 4,380,585); and Chariton et al. (U.S. Pat. No. 4,895,798); all disclose the use of tetramethylbenzidine or benzidine per se for detecting glucose in body fluids, such as blood or urine.
The patents to Pugia (U.S. Pat. No. 5,318,894); and Kardos et al. (U.S. Pat. No. 5,885,789); both disclose the use of benzidine-containing compositions per se for detecting peroxidative substances such as blood in urine or other body fluids.
All of the above patents had to use very complicated and/or expensive reagent system and are troublesome to get quick and easy test results. The use of an aqueous enzyme system makes it difficult to handle and has a limited shelf life.
Accordingly, it is an object of the present invention to provide for a test strip- a single reagent system and a method to detect and measure oxidizing adulterants in urine or other bodily fluids, being screened for drugs of abuse.
In a preferred embodiment, a 0.1 to 0.9 g of a reagent-benzidine derivative (including o-tolidine, o-tolidine dihydrochloride, benzidine, benzidine dihydrochloride, 3,5,3xe2x80x2,5xe2x80x2tetramethylbenzidine and 3,5,3xe2x80x2,5xe2x80x2tetramethylbenzidine dihydrochloride) is dissolved in 100-300 ml of a pH 5 phosphate or acetate buffer, or water and (0-50 ml) 2.5 percent Gantrez (ISP Technologies Inc. manufacturer of GAF Chemicals). A filter paper such as Whatman #3 type, or a paper of cellulose base, woven or non-woven, or other materials like fiberglass, is then soaked in the solution for 0.1 to 10 minutes. The excess solution is then squeezed out and dried in an oven at 50-75 degree C for 10-30 minutes. The amount of the benzidine derivative on the test strip is calculated to be from about 0.05 to 0.2 micromole or 0.15 to 60 microgram per 25 sq. mm (millimeter).
In an alternative embodiment, the process can be accomplished by slipping the paper material in a roll configuration and then use warm air to blow dry the material instead of putting it into an oven to dry. The roll of paper is then cut into the strip for testing purposes.
During an analysis, the paper containing the dried reagent is contacted with a liquid, such as urine, to be analyzed. After the liquid has been in contact with the dried reagent for a selected time up to 15 minutes, the paper containing the dried reagent is evaluated for detecting color change.
For a solution containing 0.5% to 20% (by volume) CHLOROX(copyright) (brand sodium hypochlorite bleach) and iodide, a blue color is detected.
For a solution containing 0.05 to 10% (by weight) pyridinium chlorochromate, a reddish-brown color is detected.
For a solution of containing 10 to 30% (by weight) hydrogen peroxide, a light blue color is detected.
For a solution containing 0.01 to 10% (by weight) of sodium nitrite, a very dark blue color is detected.
Other objects and advantage of the invention will become apparent from the following detailed disclosure.